PTO Question

[chado613]

When the rear PTO is stated as 540/1000, what does that mean ? That the PTO can operate at 2 different RPMs? Or is there actually 2 different PTO "shafts"

ALso does the 540 RPM mean at idle that is the speed its rotating?

Thanks in advance

 

[Deerherd]

When the rear PTO is stated as 540/1000, what does that mean ? That the PTO can operate at 2 different RPMs? Or is there actually 2 different PTO "shafts"

ALso does the 540 RPM mean at idle that is the speed its rotating?

Thanks in advance

Yes it means it can run at two different rpm speeds and no it's not at idle. It usually would be between 2000 and 2500 rpm, depending on the tractor to achieve the 540 pto speeds.

On my tractor I need to change the pto spline and shaft to run 1000 rpm attachments.

 

[Xfaxman]

These pictures might help, the splines are different for the two speeds.

He is holding the 540 rpm end.

 

[chado613]

Thanks guys

 

[Poopdeck Pappy]

Your tractor's tachometer should have a mark on it that says PTO. That's the revs you need to turn the engine to turn the PTO at 540 rpm.

 

[RalphVa]

Think the rear PTO is 540; whereas, any mid PTO is about double that.

Doubt you can get 1,000 rpm on the rear PTO. Your tachometer probably has a marking for 540 rpm. My JD 1025 actually tells me on the tachometer what the PTO speed is when when it's running.

Ralph

 

[GManBart]

Some machines actually have two PTO shafts so you don't have to change anything. Here's one example:

http://www.tractordata.com/photos/F004/4672/4672-td4-b03.jpg

 

[chado613]

Unfortunately when I inherited the tractor (It came with the farm when purchased), All of the gauges are not in working order.

 

[Dave M7040]

The value of the 1,000 rpm pto is that it puts less stress on the pto shaft and its joints.
The energy the shaft transmits is a direct function of the rotational speed.
Of course the energy the implement needs does not change and the gear box on the implement needs to be designed to to handle the stresses it will see.
If you take an implement and pto shaft designed for 540 and start running it at 1,000 expect serious, loud expensive problems in a hurry.
Dave m7040

 

[fitterski]

When the rear PTO is stated as 540/1000, what does that mean ? That the PTO can operate at 2 different RPMs? Or is there actually 2 different PTO "shafts"

ALso does the 540 RPM mean at idle that is the speed its rotating?

Thanks in advance

I just LOVE old threads like this one; 11-12 years on and the question still isn't answered. I don't know why someone had decided to call PTO's by speed instead of by gear ratio? My Deutz Dx-6.05 has 3 pto's: one in the front, and a 2-speed one in the rear. The 'speeds' are 1000, 540, 1000 respectively, as I start casing snowblowers for the front or rear.

PTO speeds are valid at a SINGLE engine rpm ONLY which as far as I know is the rated rpm for the engine AT which it puts out its rated horsepower but this is NO standard. My OEM tach is long gone and I'm using a chinese electrical one with no markings at all. My engine's rated (power) rpm is 2300 so for 540 rpm on the rear PTO 4.3:1 has to be the gear ratio. To make the PTO turn at 1000rpm at the same engine rpm of 2300 the ratio has to be 2.3:1. But the book says that in this single-stub configuration the reference engine RPM is 2100, suggesting ratios of 3.9 and 2.1. That stil leaves me in the dark because i don't have a 6.05 manual, only a 4.70 one with the 6.05 being a 6-jug engine instead of 4 which probably changed the story quite a bit. To put it another way the 540 PTO is more geared, it's as if it was gear 1 instead of gear 2, it also means that torque going to the implement is almost double at 540 than at 1000. Yet the manual shows different torques i.e. 1030/1180 which conflicts with my version of the reality of physics because the power curve on all engines that I know of puts out exactly the same torque at a given rpm, and that torque goes up with gearing.

I have never yet used a PTO in my life and at now at 82 I sure am still far from seeing the full picture (which is why I was googling the topic in the first place). People have advised me that a snow-blower on a 100hp machine needs a 1000rpm gearbox because of the power level which is another topic, AND a wrong argument on top of it. 100hp pto shafts are usually higher off he ground and it's this geometry that suggest an offset gearbox so that the universal joint geometry will fall into the lower regime that results in longer joint life (3deg=100%, 25degrees=5%). It so happens that virtually all these 1000rpm gearboxes (which are available reversible as well) offer gear ratios that return the 1000rpm pto shaft to the 540 which a snowblower must have (fan efficiency falls off rapidly above 600).

If I use a tractor PTO rpm of 1000 that becomes the input into a 1000rpm snowblower gearbox then I accomplish diddley squat because it's all the same as 540-to-540!

I'll be happy when I get to the bottom of all this

 

[chim]

Sorry it took me 11 years at post

I've only had one tractor with multiple PTO's. That was my B7500 that was replaced with an L3200 back in 2012. The B7500 had a rear PTO that ran at 540RPM's plus 960RPM's. There was also a mid PTO that only ran at 960RPM's.

With the PTO lever in 540, only the rear PTO ran and of course it ran at 540 with the tach on the PTO hash mark.

With the PTO leer in 960, BOTH the mid and rear PTO's ran at 960 with the tach on the PTO hash mark.

 

[ning]

Many tractors have a 2-speed PTO, 540 and some other value.

Larger tractors may have a 540/1000 PTO; the 1000 is for heavier duty equipment over 60HP as it is geared for higher RPM and have different spline pattern for hookup so they can't be confused.

Many smaller tractors have a 540/540E PTO with the 540E being "Economy" PTO setting.

This "economy" setting on smaller tractors allows you to get 540RPM without running the engine at full power. This can be useful because some equipment - such as a mower - will not work properly at other speeds, but if you're mowing much lighter material you don't necessarily need the engine's full output, so you can run eg ~1700RPM instead of eg ~2500RPM to get the necessary RPM for the mower without wasting as much fuel.

It should go without saying, but: Do Not Run Equipment Meant For 540 PTO RPM at higher PTO RPM
which once again doesn't mean you can't run it at the higher (Economy) RPM setting, just that you need to have the engine RPM at the right spot for running 540 equipment.

The instrument cluster RPM gauge will have markings for RPM bands to use for either of these speeds:

1. A mark where, when in 540 setting, the engine should be run at to get 540 RPM. If you have a 540/1000 this is probably the same spot where on the 1000 setting, you get 1000 PTO RPM; if you have a 540/540E in the 540E setting, you'll probably get something like 790 RPM, depending on your 540E gearing, and this is probably a bad place to be in the 540E setting.
2. A mark where, when in 540E setting, the engine should be run at to get 540 PTO RPM (in the normal 540 setting, the PTO RPM will be less than 540, probably more like 370).

Example from the web since I'm too lazy to go take a pic of my dash:

This example is on a tractor with 540 and 540E; you can see that you're expected to have RPMs in the 1700-1800 range for the 540E and 2450-2600 for 540 -- in both cases this is for 540 PTO RPM output.

 

[masscity]

My B7100DT I bought new in 1978 has a front PTO for a bottom mower I didn't buy and a 3 speed rear PTO.